Machine for calibrating gun-barrels.



C. W. SPONSEL. MACHINE FOR CALIBRATING GUN BARRELS.

APPLICATION FILED JULY I7. 1916- Patented fiept. 11, 1917/.

4 SHEETSSHET I- C. W. SPONSEL. MACHINE \FOR CALIBRATING GUN BARR ELS.

APPUICATION FILED J ULY 17,1916.

Pafented Sept. 11,1917.

4 SHEETS-SHEET 2.

C. W. SPONSEL. MACHINE 'FOR CALIBRATING GUN BARRELS.

APPLICATION FILED JULY N11916- Patented Sept. 11, 1917.

4 SHEETS-SHEET 3- ELS.

APPLICATION FILED JULY I7. 1916.

Patented Sept. 11, 1917'.

.4 SHEETS-SHEET 4.

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CHARLES W. SPONSEL, OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE SPONSEL COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

MACHINE FOR CALIBRATING GUN-BARRELS.

Specification of Letters Patent.

Patented Sept. ii, ieiv.

Original application filed. February 28, 1916, Serial Ito. 80,959. Divided and this application filed July 17,

1916. Serial No. 109,600.

To aZZwhom it may concern:

Be it known that I, CrIARLns TV. SroNsnL, a citizen of the-'United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Machines for Calibrating Gun-Barrels, of which the following is a specification.

This invention relates to a machine which is more particularly designed to calibrate on detect and measure the defects in the bores of gun barrels and similar tubes and it is a division of the invention, or is a continuation of so much as is common to the invention shown, described and claimed in my copending application Serial No. 80,959, filed February 28, 1916 for machine for straightening gun barrels.

The object of the invention is to provide a simple machine into which gun barrels and similar tubes can be quickly placed, tested and removed, that has means which will electrically indicate small deflections inthe bores and mechanically measure the amount of variation from true.

As the invention claimed herein is particu larly adapted for use with means by which the barrels or tubes can be bent and straightened until such inaccuracy as is indicated by the electrical means and measured by the mechanical means is overcome, it is illustrated and described as incorporated in a. gun barrel straightening machine.

The machine illustrated has yielding centers for supporting a barrel at the breech and muzzle, These centers are mounted so that they may be moved sidewise of the machine for carrying the barrel lengthwise, and they are also capable of upward movement so as to allow the ends to spring upwardly when the barrel is being straightened. A wire, secured at one end by a fixed clamp, is arranged to be threaded through the barrel and supporting centers, and after its other end is secured by a yielding clamp, be drawn tight and held taut with a spring tension. The wire clamp supports are mounted so that they may be lowered and raised a slight distance and cary the wire down or up, this distance being measurable by a micrometer gage. The wire is connected in an electric circuit containing lamps, and at the middleof the machine is provided with a conducting feeleror contact that is adapted to be engaged with or disengaged from the wall of the bore of the barrel as the wire is lowered or raised. One of the circuit terminals is connected with the wire, the supports of which are properly insulated, and the other terminal is grounded on the ma chine. The circuit is so planned that when the wire contact is caused to touch any point along the bore of the barrel the circuit conditions will be changed in such manner that the lamps will show the altered relation, and the gage will show the amount of movement which caused the change. Associated and cooperating with the electrical indicating and mechanical measuring means is mechanism arranged to bend the barrel while i in testing position and restore the electrical condition, and thus show a rectification of whatever irregularity is indicated and measured, although the bending mechanism forms no part of the invention claimed herein.

Figure l of the accompanying drawings shows a front elevation of the machine.

Fig. 2 shows a plan. Fig. 3 is a diagrammatic illustration of the method of indicating the accuracy of the bore. Fig. 4 is a view of the electrical contact that is threaded through the barrel. Fig. 5 is a face view of the same. Fig. 6 shows an elevation of the machine. Fig. 7 is a vertical section on the plane indicated by the line 7-7 on F 2. Fig. 8 is a vertical longitudinal section through the barrel. Fig. 9 is a sectional view showing the wire clamping and stretching mechanism at the lefthand end of the machine. Fig. 10 shows a side view of one of the barrel supporting centers and the ad jacent mechanism. Fig. 11 shows a plan of the same. Fig. 12 is a vertical section on the plane indicated by the dotted line 1212 on Fig. 11.

The bed 1 of the machine is mounted on a column 2 having a widened base 3. A slide l is arranged to move back and forth in a guideway that extends from side to side in the top of the bed. On the bottom of this slide is a rack 5 engaging with which is a pinion 6 on a'shai't 7 that at the front is provided with a hand wheel 8. A head 9 is adjustably fastened on the top of the slide near each end. Pivoted to each head is an arm 10, and hinged to each arm is a block 11 which holds a tubular barrel supporting center 12. The centers at the top are slotted 15. Each block is guided at the front when p it .moves up and down by a vertical groove in the back surface of the front part of the head. Each center is pushed toward the middle of the machine by a flat spring 16, that engages with a pin 18 which extends downward from the center (Fig. 10) and the center at the left is arranged to be drawn back by a hand lever 17 that is pivoted to the block by screw 171 and engages with a pinlS which projects from the center. To put a barrel into the machine the center at the left is drawn back and when one end of the barrel is placed on the center at the right the left center is allowed to spring forward into the barrel at that end. When mounted this way the barrel can be moved lengthwise across the machine by turning the hand wheel at the front. The heads are located on the slide according to the length of the barrels to be straightened.

The indicator wire 19, which is designed to pass through the barrel and through the barrel supporting centers, is secured at its ends by clamp levers 20 which are pivotally mounted on blocks 21 secured at the ends of rocker arms 22 that project forwardly from a rocker shaft 23 that extends lengthwise of'the machine at the back. The rocker shaft is preferably mounted in fiber bushings 2% placed in brackets 25 attached to the back of the bed so it can rotate without moving longitudinally, and will be electri cally insulated from the rest of the machine. The clamp levers are provided with hand screws 26 which, when turned one way, cause the jaw ends of the clamps to bite the ends of the wire against teeth on the clamp blocks, and when turned the other way allow the jaws to open and release the ends of the wire. The clamp block with the clamp lever at the left hand end of the machine is slidable horizontally in the endof the arm for tightening the wire. This clamp block has a threaded stem 27 on which turns a hand nut 28. A spring 29 is arranged on the threaded stem between the nut and the end of the arm so that when the nut is turned up for tightening the wire the spring will be compressed and thus hold the wire taut but with a yielding tension. Bars 30 extend across the top from the front of the arms 22-, which carry the wire clamps, to other arms 31 which are fastened to the rocker shaft near the middle of the machine. These bars not only stiffen the wire clamp supports and insure that they move together, but they are arranged so that they so that the wire will not be sheared off or broken by the bending of the barrel.

The rocker shaft has attached to it a lever arm 32 that engages a nut 33 held from rotation by a bracket 3a fastened to the back of the bed. Turning in this nut is the rear end of the arbor 35 on the front end of which is secured the hand wheel 36. Frictionally held on the hub of the hand wheel by a thumb screw 37 with a tapered inner end and a plunger 38 with-a tapered inner end is the index wheel 58. hen the tapered inner end of the screw is forced against the tapered inner end of the plunger the latter is forced out against the inner wall of the hub of the index wheel. The index wheel is graduated on its periphery in thousands of an inch. When the index wheel is turned one way the nut is drawn forward in such manner as to cause the lever to rock the shaft and turn up the arms and raise the indicator wire. Then the index wheel is turned in the opposite direction the nut is moved backward and the weight of the arms and connected parts carries the indicator wire downward. If the thumb screw is loosened the graduated index wheel is released so that it can be turned around and set to zero. As the rocker lever is not attached to the nut, but merely held against it by gravity, the parts are free so that the wire may be lifted whenever the centers are carried up by any bending of a barrel. The lower end of the rocker lever is insulated from the nut by a piece of insulation 39.

l'Vedge shaped blocks 410 are mounted so that they are free to be moved toward the front and back in slides 41 that are free to be moved along the top of the bed.

from side to side. By moving the slides longitudinally of the machine the wedge shaped blocks may be located anywhere that it is desired along the length of the barrel, and by pushing the blocks backward they may be brought into contact at the required places with the barrel held by the centers. At the centerof the machine and projecting forwardly is a bending arm 42 that is pivoted on pin 422 (Fig. 7) to the bed near the back and at its front end over the center of the barrel is provided with a heavy screw 43 which may beturned down or up by hand or by means of a wrench. The rear end of the bending arm is pivotally connected with the upper end of. a link 4& that is supported by a link/15 which is jointed to the column. The lower end of the link 44 is connected by a short toggle arm 460 with the bent end of the treadle 1ever which is pivoted to the base and at the front of the machine is provided with a foot pad 47. When the treadle is depressed by means of this toggle and link connection the bending arm is forced down with great power. The treadle may be held down by a lock bar 48 if desired, or it may be locked up by a safety catch 49. The treadle is raised by a spring 50 arranged inside of the column. A yielding cushion 51 is attached to the back of the column in such manner as to prevent the toggle from becoming locked on center.

Small lamps 52, preferably red and green, are located in a box 53 attached to the front of the bed and adjacent to this is a switch 5-1. Secured to the back of the bed may be a fuse block 55 and attached to the underside may be a transformer 56. Line wires are connected with the fuse block which is connected with the switch. The circuit wires run from the switch to the transformer and then to the lamps. One end of the circuit is grounded on the machine, while the other end is connected with the indicator wire, the supports of which are, as above described, electrically insulated from the rest of the machine. On the indicator wire at the center of the machine and directly below the bending screw is a conducting ieeler or contact 57. The conducting teeler on the wire at the middle of the machine and below the bending screw is arranged so as to always point downward.

In using this machine the ends of the barrel which have been slightly reamed out are placed on the centers with the indicator wire threaded through the barrel and laid in the centers. The free end of the wire is then clamped and the wire drawn taut. The barrel may first, if necessary, be rough straightened by rotating it on the centers and mov ing it along until the highest spot ot the bend comes beneath the bending screw. The blocks are moved along to the desired place and pushed back, and then the bending screw is brought down by pressing on the treadle. This may be continued until the barrel is in such condition that the indicator wire will not touch at either end. hen this has been accomplished the barrel is moved along until one end is at the center and then the wire is lowered by turning the index wheel until the contact touches the bottom of the bore of the barrel. This grounds the circuit and one of the lights will go out. The index wheel is then set to zero. The barrel is then rotated to see if the centeron which it is mounted is true with the bore. The barrel may then be pushed over until the other end is at the center. The wire is again lowered until the til contact engages the bottom of the bore and the light goes out. If the ends are true the index will show Zero. The barrel is then turned around to see whether it is mounted true on the center at this end. After this the barrel is pushed along from end to end and rotated to find out where the high spots are, how long the curves are, and the amount of deflection. The barrel is then moved along until the highest point is beneath the bending screw and the blocks pushed beneath it. The treadle is depressed, bringing down the bending screw. and bending the barrel. This is repeated until with the in deX at zero the lights will both stay on as the barrel is rotated. lVhen the barrel can be moved to every position and can be rotated in any position and both lights will stay lighted with the index at zero, it is known that the bore is absolutely straight. As a very small current is employed and the lamps are small and the contact is very delicate, deflections of .0001 of an inch in the barrel will be indicated.

The invention claimed is:

1. A machine for calibrating gun barrels having means for supporting a barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for imparting a relative transverse movement between the wire holding means and the barrel, a contact on the wire and adapted to be engaged with any point along the wall of the bore of the barrel, and means for indicating outside the barrel the engagement of the contact therein,

said means being automatically controlled by such engagement.

2. A machine for calibrating gun barrels having supports for a barrel, means for moving the barrel supports together in the direction of the aXis of the barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for imparting a relative transverse movement between the wire holding means and the barrel, a contact on the wire and adapted to be engaged with any point along the wall of the bore of the barrel, and means for indicating outside the barrel the engagement of the contact therein, said means being automatically controlled by such engagement.

3. A machine for calibrating gun barrels having means for supporting a barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for moving the wire holding means transversely of the barrel, a contact on the wire and adapted to be engaged with any point along the wall of the bore of the barrel, and means for indicating outside the barrel the engagement of the contact therein, said means being automatically controlled by such engagement.

therein, said means being automatically controlled by such engagement.

5. A machine for calibrating gun barrels having supports for a barrel, means for moving the barrel supports together in the direction of the axis of the barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for imparting relative sidewise movement between the wire holding means and the barrel, a contact on the wire and adapted to be engaged with any point along the wall of the bore of the barrel, an electrical circuit adapted to be closed by such engagement of said contact, and means controlled by closure of said circuit for indicating the engagement of the contact with the wall. of the bore.

6. A machine for calibrating gun barrels having means for supporting a barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for moving the wire holding means transversely of the barrel, a contact on the wire and adapted to be engaged with any point along the wall of the bore of the barrel, an electric circuit adapted to be closed by such engagement of said contact, and means controlled by closure of said circuit for indicating the engagement of the contact with the wall of the bore.

7. A machine 01- calibrating gun barrels having supports for a barrel, means for moving the barrel supports together in the direction of the axis of the barrel, a wire adapted to be threaded through the barrel, means for holding the wire taut when so threaded, means for moving the wire holding means transversely of the barrel, a contact on the wire and adapted to be engaged with any point along the bore of the barrel, an electrical circuit includingthe wire, contact and barrel supports and means for i11- dicating the engagement of the contact with the wall of the bore ofa barrel held by said support.

8. A machine for calibrating gun barrels having supports for a barrel, means for moving the barrel supports together in the direction of the axis of the barrel, an electric circuit including the barrel supports and a contact adapted to be located in the bore of the barrel, and electrically excited means included in said circuit to indicate engagement of said contact with the wall electrically excited means included in said circuit to indicate the engagement of said contact with the wall of the bore of the barrel.

1.0. A machine for calibrating gun barrels having means for supporting a barrel, an

electrical conductor adapted to be passed into the bore of a barrel held by said supporting means, a conducting contact on said conductor and adapted to be engaged with any part of the wall of the bore of such barrel, a source 01 electrical energy connected with said conductor and with a barrel placed in the supporting means, and an electric lamp interposed in the electrical circuit.

CHARLES WV. SPONSEL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of l atents, Washington, D. G. 

